office



H. W. MoALL.

TEMPLBT FOR DRAWING RAILWAY SWITCHES AND CHOSSOVERS.

APPLICATION FILED APR.11, 101s.

1,105,809. Patented Aug. 4, 1914.

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A L) w Witnesses. I Inventor.

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THE NORRIS PETERS CO. PHOTO-LITHU. WASHINGTON, D, C

nnrrnn STATES rarrnnr OFFlGE.

HENBY'WARDLAW eant, or ronon'ro. on'rnnro, CANADA.

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.TE'MPLET FOR DRAWING RAILWAY SWITCHES AND CROSSOVERS.

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To all whom it may concern Be it. known that I, I'IENRY WARnLAw McKLL, a subject of the King of Great Britain, andreside-ntof the city of Toronto, county of York, Province of Ontario, in

the Dominion of Ga'nada, have invented certain new and useful Improvements in Templets for Drawing ltailway Sw1tches and Crossovers, as described in the following specification and illustrated in the accbm anying; drawings, that/form part of thesamep lhevprincipal objects of the invention are, to effect a saving of time in the laying,

out of drawings of railway switches and crossovers, and to devise a ten'iplet for the draftsmans use which will give the required distances and curves necessary for indicating such switches and crossovers 1n the standard scales. The principal feature of the invention consists inthe novel formationof the templet whereby the reverse curve of a switch or crossover may be drawn with one operation and the proper intermediate tangent portion indicated.

A further important feature consists 1n the novel means for giving the spacing,

distances for the rails.

In the drawings, Figure 1 is a. plan view of a templet constructed in accordance with this invention. Fig. 2 is a View illustrating the class of drawing in which the device is used. Fig. 3 is an enlarged perspective detail of one end of the t-emplet showing the track spacing portion.

Like numerals of reference indicate corresponding parts in each figure.

Referring to the drawings, 1 is the templet which may be made of any suitable material but is preferably formed of a strip of sheet celluloid or transparent xylonite. The edge 2 of the templet is formed with an inward curved portion .3 toward each end and the said curve merges into a tangent a leading to a curve 5, the reverse of the curve 3. The edge 6 of the templet continues from the curve 5 and is tangential thereto and parallel with the edge 2 and spaced the proper distance therefrom cor- Specification of Letters Patent.

The points 7 and 8 indicate the distance between the terminal With a tcmplet of this kind an engineer or draftsinan may lay out the track curves used in crossovers and switches very rapidly and the marks given thereon for each such Patented Aug. 4:, 1914.. Application filed April 11, 1913. Serial No. 760.470. h

curve enable him to determine the exact locations of the switches and frogs. 1n the templet herein illustrated Ishow two forms of switches and crossovers,

namely, one with two Number 10 fro s and the other using-two Number 7 frogs and the distance between centers of tracks vide on onesidetwo compound crossover curves, one the reverse of the other for each number of frog so that whatever may be desired may be laid out by the draftsman very quickly.

In "order to further facilitate the work of the draftsman in drawing tracks, I provide a special track gage on one of theedges of the scale preferably at the end. This gage is formed by cutting a notch 11 in the end of the scale. The bottom of the notch 11 is formed with a plurality of minor notches 12 arranged in two or more pairs and said pairs are spaced apart with their centers corresponding with the distance between the straight edges 2 and 6 of the scale. The edges of the notches 11 and 12 are beveled so that sloping clefts 13 are formed intowhich the point of a pencil may be inserted very the left hand or right hand notch of each pair will be employed. Thetracks will thus all be uniformly spaced. The arrangement of the spacing-notches is an important feature and may be used forany standard spacing saving time to a draftsman and greatly increasing the accuracy of the work.

It will be seen that with a templet of this kind the draftsman may. lay down his track lines and wherever a switch or a crossover is desired he simply has to lay thetemplet down upon the track lines and draw the compound or reverse curve in position with whichever frog is desired.

The templet will of course be provided for various scales and for any required frog,

the oneherein shownbein indicated as on a scale of one inch to one undred feet and for frogs Number 7 and Number 10.

The application of the use of this 'templet for drawing the rails is shown in the draW-' ing as indicating both rails but it will of course be equally applicable to drawings where-the track is indicated by a singlecenter line.

. tending straight edge portion, a tangent curve e5? from the Mid 0f said central straight edge leading 't'o an angularly set tangent, a curve joined .to'said tangent and forming the reverse of the aforesaid curve, and a straight edge meeting the latterzedge tangentially, said latter straight edge being arranged in parallel relation with the central straight edge-portion and spaced a set distance laterally therefr.om., i

' 3. A templet having a central straight edge portion and compoundjreverse curves extending tangentially therefrom "and merging into straight end portions arranged one o in alinement with the other and'spaced a prescribed distance laterally in relation to the central straight edge portion.

Signed atthe city of Toronto, county of i 1 York, Province of Ontario, in'the- Dominion of Canada, this 1st day of April 1913. a I HENRY WARDLAWMCALL.

Witnesses:

A. G. KELLY,

H. L; TRIMBLE; I

Copies of this patent may be obtained for .five cents each, by addressing the Commissioner 0! Patents. Washington, D. 0. .7 

